1. Field of the Invention
Embodiments of the invention include methods and apparatus that are generally directed to addressing the effect of presbyopia, and which are more particularly directed to addressing solutions to the problem of presbyopia through corneal accommodation.
2. Description of Related Art
The eye is a multi-component structure providing multiple functions for forming images and enabling sight. A master diagram of the basic anatomy of the human eye 10 is shown in FIG. 1. In very general terms, the anterior portion 19 of the eye includes the cornea 4 and the sclera 5. The cornea is the outer, transparent, domelike structure that covers the iris 2, pupil 3, and anterior chamber. The cornea provides approximately seventy percent of the optical power of the eye. The tough, white, outer layer of the eyeball is called the sclera. In combination with the cornea, the sclera protects the entire eyeball. The crystalline lens 6 is located posterior to the cornea and is held in place by fibers controlled by the ciliary muscles, which enable the crystalline lens to change shape for focusing. The retina 12, located at the back of the eye, is the image forming surface of the eye.
The total eye structure operates to receive light coming from an object and form an image of the object on the retina. As mentioned above, the cornea provides the bulk (˜70%) of the refractive power of the eye for focusing incoming light onto the retina Common vision defects referred to as nearsightedness (myopia) and farsightedness (hyperopia) typically result from a misshaped corneal surface that either provides too much focusing power or too little focusing power resulting, in any event, in a blurry image. The crystalline lens and the muscle (ciliary) control structures associated therewith provide the eyes with the ability to accommodate; that is, to focus both on objects that are very far away and objects that are very close. However, with age, the crystalline lens in the human eye stiffens and loses its ability to change its shape and/or position in response to the desire to view an object that is close to the viewer's eyes. This condition is referred to as presbyopia, which is the inability of the eye to accommodate. Unfortunately, one hundred percent of the population will develop presbyopia by the time they are fifty years old, give or take several years.
Presbyopia is typically addressed by auxiliary lenses in the form of spectacles or contact lenses that provide the extra focusing power for viewing close-up objects. Spectacle lenses can be of the bifocal or multi-focal type, which provide different lens regions with different focusing powers so that a range of near distance viewing is made possible. Alternatively, contact lenses of the alternating vision type or the simultaneous vision type provide either multiple viewing zones similar to multi-focal spectacles, or provide a near focus and a far focus image simultaneously and rely on the brain to discriminate for the actual view.
Due to the enormous market for presbyopia correction, new methods and devices for addressing the problem are in constant development. For example, scleral bands, refractive laser surgery, accommodating intraocular lenses (IOLs) and other techniques are being used to treat presbyopia. However, treatments to date have not provided optimized results, and many of the proposed treatments are severely invasive in nature and thus traumatize the optical zone of the eye.
Accordingly, the inventor has recognized the need for a method and apparatus improvement useful for addressing the problem of presbyopia, and that overcome the shortcomings in the current state of the art, and which offer benefits and advantages associated with the successful treatment of presbyopia.